@misc{indiciaeafb0266a63e2,
  title = {Ground-water levels in the United States, 1957-61, North-central states},
  author = {O. M. Hackett},
  year = {1964},
  doi = {10.3133/wsp1781},
  url = {https://pubs.usgs.gov/publication/wsp1781},
  note = {Source identifier: wsp1781}
}